Numerous bed bug research papers have been published in the past 20 yr as a result of bed bug (Cimex spp.) (Hemiptera: Cimicidae) resurgence in the world.Yet, few of them focused on the management of ...the tropical bed bug, C. hemipterus (F.). Here, we describe a case of tropical bed bug infestation in two dormitory buildings and effectiveness of a tropical bed bug treatment program. The study site consisted of 125 dormitories in two buildings. An initial building-wide monitoring with ClimbUp interceptors revealed 25 infestations. The spatial distribution of bed bug infested rooms showed a significant aggregated distribution pattern with same infestation status for neighboring units sharing walls. All infested rooms were monitored every 2 wk and treated using a combination of steam and diatomaceous earth (DE) dust application if bed bugs were still found. For the 25 initially identified infested rooms, after 14 wk treatment, 44% of them no longer had bed bugs, and the mean number of bed bugs captured per room decreased by 94.1%. A combination of steam and DE dust treatment is an effective strategy for suppressing tropical bed bug infestations in dormitory environment.
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•EGCG @ BSP/ HA MNs can be administered in situ for the treatment of acne vulgaris.•The microneedle backing material with DE adsorbs pus for simple debridement, effectively preventing ...secondary infections.•The microneedle body material is natural polysaccharide with good biocompatibility, dissolving and releasing EGCG rapidly.•EGCG is a natural polyphenol with highly effective antibacterial and anti-inflammatory properties.
Acne vulgaris is a common inflammatory skin disease associated with Propionibacterium acnes (P. acnes), with serious physical and psychological effects on patients. Conventional topical use of antibiotics is not effective due to the skin barrier and oral administration can adversely affect the intestinal flora. Microneedle is a novel type of localized drug delivery system that noninvasively breaks through the stratum corneum barrier and effectively enhances the transdermal absorption of drugs. Here, Bletilla striata polysaccharide (BSP)/Hyaluronic acid (HA) loaded Epigallocatechin gallate (EGCG) was used as the microneedle body to easily penetrate the epidermis and enhance antibacterial ability. Polyvinyl alcohol (PVA) and Diatomaceous earth (DE) are used as the microneedle backing to absorb pus and bacterial debris, prevent re-infection of bacteria and promote skin healing. Compared to traditional antibiotics, the excellent skin permeability of EGCG@BSP/HA MNs studied here can improve the efficacy and solve side effects and drug resistance. In vivo studies in mice models induced by P. acnes showed that this microneedle could effectively reduce skin swelling, inhibit bacterial growth and reduce the levels of TNF-α, IL-8 and MMP-2. In summary, this study provides an ideal antimicrobial drug delivery system for the treatment of acne vulgaris.
Reducing farm-level grain storage losses for small-scale rural farmers is important for sustainable household food security in Africa. Farmer-managed trials were conducted over two 32-week grain ...storage seasons in Zimbabwe to evaluate the effectiveness of diatomaceous earths (DEs); Protect-It® and Chemutsi (raw local DE), enhanced with low doses of deltamethrin or spinosad as protectants of stored maize grain for control of major storage pests: Sitophilus zeamais, Prostephanus truncatus, Tribolium castaneum and Sitotroga cerealella. Five combinations of DE-spinosad and DE-deltamethrin were compared against a commercial insecticide mixture of pirimiphos-methyl + deltamethrin and an untreated control. Treatment effects on insect numbers, grain damage and weight loss, and grain moisture content were assessed at 8-week intervals. Protect-It® 0.1% + deltamethrin 0.0005% w/w, Protect-It® 0.05% + spinosad 0.005% w/w, and Chemutsi 0.1% + spinosad 0.0075% w/w were the most effective (P < 0.001) treatments when all efficacy parameters were considered. These low-dose DE-based combinations have potential to replace organophosphate-based commercial grain protectants currently used in small-scale grain storage systems and thus contribute towards improved household food security and safety in Africa.
•Two low-dose DE-spinosad and one low-dose DE-deltamethrin combinations were effective.•Use of DE-spinosad or DE-deltamethrin combinations require re-treatment at 24 WAT.•Farmer practices (Eleusine coracana husks; Eucalyptus fresh leaves) were ineffective.•Prostephanus truncatus occurred in treated grain and Sitophilus zeamais was dominant.
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► Critical assessment of published work on raw and modified diatomites. ► Counter-ion effect on the extraction of heavy metal speciation by diatomite. ► Selection of the counter-ion ...by the use of existing thermodynamic data. ► Enrichment of diatomites by attaching heavy metal selective functionalities. ► Supramolecular chemistry for conferring selectivity to diatomites.
Contamination of water by heavy metals is a global problem, to which an inexpensive and simple solution is required. Within this context the unique properties of diatomite and its abundance in many regions of the world have led to the current widespread interest in this material for water purification purposes. Defined sections on articles published on the use of raw and modified diatomite for the removal of heavy metal pollutants from water are critically reviewed. The capability of the materials as extracting agents for individual species and mixtures of heavy metals are considered in terms of the kinetics, the thermodynamics and the recyclability for both, the pollutant and the extracting material. The concept of ‘selectivity’ for the enrichment of naturally occurring materials such as diatomite through the introduction of suitable functionalities in their structure to target a given pollutant is emphasised. Suggestions for further research in this area are given.
The purpose of this study was to determine the effect of partial replacement of cement with diatomaceous earth (DE) on the compressive strength and absorption of mortar. The cement volume was ...replaced by different contents of replacement levels of 0%, 10%, 20%, 30% and 40% DE. Ordinary Portland Cement (OPC) and Portland Composite Cement (PCC) were used while the binder and sand were mixed at 1: 2 and 1: 4 vol ratios. Moreover, 5 × 5 × 5 cm3 cubes were used as the test specimens and their compressive strength was determined at 1, 3, 7, and 28 days while the absorption was evaluated at the curing age of 28 days. The results showed that the compressive strength of mortar with OPC for both 1: 2 and 1: 4 ratios decreased with the increment in the content of the DE. However, at 40% cement replacement, the mortar with OPC was categorized as type M according to SNI 6882:2014 or ASTM C270-10 with 28 days compressive strength observed to be greater than 17.2 MPa. Meanwhile, the mortar with PCC for 1: 2 was observed to have the highest compressive strength of 36.63 MPa at 20% cement replacement and 25.39 MPa at 10% cement replacement for 1:4. Furthermore, the absorption of mortar with DE was observed to be greater than for mortar with cement only.
► Prussian blue was sealed in cavities of diatomite using carbon nanotubes. ► The caged Prussian blue after being permanently immobilized in polyurethane spongy showed a 167mg/g capability for ...absorbing cesium. ► Cesium elimination was accomplished by simply adding the Prussian-blue based spongiform adsorbent to radioactive water.
We developed a spongiform adsorbent that contains Prussian blue, which showed a high capacity for eliminating cesium. An in situ synthesizing approach was used to synthesize Prussian blue inside diatomite cavities. Highly dispersed carbon nanotubes (CNTs) were used to form CNT networks that coated the diatomite to seal in the Prussian blue particles. These ternary (CNT/diatomite/Prussian-blue) composites were mixed with polyurethane (PU) prepolymers to produce a quaternary (PU/CNT/diatomite/Prussian-blue), spongiform adsorbent with an in situ foaming procedure. Prussian blue was permanently immobilized in the cell walls of the spongiform matrix and preferentially adsorbed cesium with a theoretical capacity of 167mg/g cesium. Cesium was absorbed primarily by an ion-exchange mechanism, and the absorption was accomplished by self-uptake of radioactive water by the quaternary spongiform adsorbent.
Potassium‐ion hybrid capacitors (KICs) reconciling the advantages of batteries and supercapacitors have stimulated growing attention for practical energy storage because of the high abundance and low ...cost of potassium sources. Nevertheless, daunting challenge remains for developing high‐performance potassium accommodation materials due to the large radius of potassium ions. Molybdenum diselenide (MoSe2) has recently been recognized as a promising anode material for potassium‐ion batteries, achieving high capacity and favorable cycling stability. However, KICs based on MoSe2 are scarcely demonstrated by far. Herein, a diatomite‐templated synthetic strategy is devised to fabricate nitrogen‐doped MoSe2/graphene (N‐MoSe2/G) composites with favorable pseudocapacitive potassium storage targeting a superior anode material for KICs. Benefiting from the unique biomorphic structure, high electron/K‐ion conductivity, enriched active sites, and the conspicuous pseudocapacitive effect of N‐MoSe2/G, thus‐derived KIC full‐cell manifests high energy/power densities (maximum 119 Wh kg−1/7212 W kg−1), outperforming those of recently reported KIC counterparts. Furthermore, the potassium storage mechanism of N‐MoSe2/G composite is systematically explored with the aid of first‐principles calculations in combination of in situ X‐ray diffraction and ex situ Raman spectroscopy/transmission electron microscopy/X‐ray photoelectron spectroscopy.
Nitrogen‐doped MoSe2/graphene composites prepared via a biotemplated strategy are employed as highly effective anodes for potassium‐ion hybrid capacitors, manifesting high energy/power density (119 Wh kg−1/7212 W kg−1) and long lifespan.
To ameliorate adsorbent recovery by an external magnetic field, naturally occurring diatomaceous earth (DE) was modified with iron-oxide, characterized and applied for adsorption of carbamazepine ...(CBZ) from synthetic wastewater using batch equilibration method. The fabricated adsorbent was characterized using XRF, XRD, SEM-EDX, FT-IR, BET surface area analysis, VSM and pH of point of zero charge (pHpzc) determination. The adsorption rate was described by the pseudo-first-order (PFO) model suggesting a physisorption controlled rate-determining step. Equilibrium adsorption data were fitted to linear and nonlinear isotherm models, viz Langmuir and Freundlich models, and were best described by Freundlich nonlinear equations implying heterogeneous multilayer adsorption. The best-fitting kinetic and isotherm model was determined using four mathematical error functions. The thermodynamic parameters, namely enthalpy (ΔH = −26.4 kJ mol−1), Gibbs free energy (ΔG = −2.22 kJ mol−1 at 298 K), entropy (ΔS = −34.0 kJ mol−1), indicated that the adsorption was a spontaneous, exothermic, and physical process. The adsorption mechanism is postulated to involve cation-π interactions. Modified diatomaceous earth is a potentially excellent, low-cost, and novel sorbent for CBZ adsorption with 88% removal in 180 min and provides a possible alternative adsorbent for wastewater treatment.
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•Magnetic diatomaceous earth (Fe-DE) was prepared by simple wet impregnation using iron salts.•Fe-DE can remove up to 88% of Carbamazepine from water in 180 min.•Adsorption was described by the Freundlich and pseudo-first-order models.
•Blocking filtration laws are applied to evaluate filter aid filtration data.•Cake filtration law and missing law are identified as relevant process laws.•X-ray microscopy is used to visualize the ...separation mechanisms.•A separation principle can be assigned to the missing law, for the first time.
In this study, the blocking filtration laws introduced by Hermans and Bredée are applied to evaluate filter aid filtration data. A model system is utilized for the filtration experiments, consisting of barium sulphate as the model impurity and diatomaceous earth as the filter aid. Based on the analysis of the filtration data, the relevant process laws are initially identified as cake filtration for the separation of the diatomaceous earth and the so-called missing law for the separation of barium sulphate. The results are substantiated with the aid of X-ray microscopy to monitor the incorporation of the fine particles in the filter aid structure. They demonstrate that the separation of barium sulphate is characterised by both depth migration and accumulation within the growing filter aid structure. The blocking filtration laws derive from a general exponential relationship between blocking rate φ and hight-specific resistance r with the blocking exponent n. Hermans and Bredée presented first the solutions for the four blocking exponents n=2 (complete blocking), n=1.5 (standard law), n=1 (intermediate law) and n=0 (cake filtration). Gonsalves later supplemented the solution for n = 0.5 from a purely logical point of view and called it the missing law, as he could not find a model behind it himself. Thus, for the first time, this study assigns a separation principle to the missing law, which until now has only been discussed theoretically.
Multifunctional composite materials with controlled release, antimicrobial and antioxidant properties were prepared through encapsulation of oregano essential oil (OEO) into diatomaceous earth (DE) ...and halloysite nanotubes (Hal). DE-OEO and Hal-OEO composites were compared with their physicochemical and functional properties such as the morphology and elemental analysis, zeta-potential, chemical structure, crystallinity, thermal stability, specific surface area, encapsulation efficiency, release rate, antioxidant, and antimicrobial properties. Pristine DE showed a sunflower-like shape with an average diameter of 24 μm, zeta-potential of −47.3 mV and BET of 0.87 m2/g. Whereas Hal exhibited a tubular structure with an average length of 788 nm and width of 115 nm, zeta-potential of −19.7 mV and BET of 68.5 m2/g. The morphology and crystallinity of DE and Hal did not change significantly after OEO loading, whereas FT-IR results confirmed that OEO was successfully loaded into DE and Hal. The thermal stability of OEO was improved after being encapsulated into Hal and DE. Both samples showed high antioxidant and antimicrobial activities. However, the DE-OEO sample exhibited stronger antioxidant and antimicrobial activities than Hal-OEO due to its higher encapsulation efficiency and release rate. Prepared materials can be used as a controlled-release, antioxidant, antimicrobial, nanofiller for food packaging, and drug delivery applications.
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•Oregano essential oil was successfully encapsulated on the mesoporous DE and Hal.•Encapsulation efficiency of DE-OEO was higher than those of Hal-OEO.•DE and Hal were significantly improved the thermal stability of OEO.•Release of OEO from DE-OEO was 1.4–2.1 times higher than that from Hal-OEO.•DE-OEO showed better antioxidant and antimicrobial activity than Hal-OEO.
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